European forests cannot further curb global warming, French study warns

European countries should not heavily rely on their forests to absorb carbon dioxide but instead preserve them from climate change, according to a study published on Wednesday (10 October) in the scientific journal Nature. EURACTIV France reports.

The Paris Agreement of 2015 mentions the importance of forests as carbon sinks because they are capable of removing CO2 from the atmosphere.

Researchers have studied various forest management strategies in Europe, such as maximising CO2 storage or reflecting more light which is then directed back into space.

However, those simulations do not take into account possible reforestation or deforestation.

The amount of carbon removed by trees over 90 years (2 parts per million) is reportedly low compared to the quantity of CO2 released into the atmosphere if global warming continues on its current course.

This scenario would represent around 500 parts per million, according to Guillaume Marie, a climatologist at the Université de Paris-Saclay.

In order to absorb 8 billion tonnes of CO2 by 2100, conifers would need to replace deciduous trees over an area equivalent to that of Spain. Conifer trees would be the best species for removing carbon in this part of the world. However, their darker colour would undo these gains by driving global warming, the researchers explained.

“The standard mistake is thinking that CO2 sequestration means climate cooling,” Marie told AFP. “This is the case if we don’t change the planet’s optical, chemical and physical properties. But, by promoting coniferous forests over deciduous forests, we are changing the colours of leaves”.

Under the Paris Agreement, the EU committed to reducing its greenhouse gas emissions by 2020 by at least 40% compared to 1990, relying on forests to achieve around a quarter of this objective.

At the same time, the European Union, which has 182 million hectares of forests (42% of its area) is seeing this heritage damaged by droughts, storms, insect pests and human beings. In April, the Court of Justice of the European Union charged Poland, which will host COP24 in December, with chopping down parts of its thousand-year-old forest.

The study recommends that governments instead concentrate on protecting these ecosystems and adapting forests to the changing climate so that they can still perform their ecological and economic roles.

Large-scale reforestation in Europe could significantly reduce CO2 emissions but Marie believes this scenario is highly unlikely given the continent’s relatively high population density.